In the video, it looks like fire came after water. A fire started halfway through the video (within 15 minutes of the arrival of the tsunami). Then a big neighborhood across from the river became swallowed up by flames. Fire often accompanies disasters, and in this case you might be left without anywhere to run to.

The people in the video also seemed incredibly calm. Or they just didn't verbalize their panic. "Well, it's a tsunami. Let's take some pictures while the whole neighborhood goes underwater or goes up in smoke." In the US, people would be screaming their heads off.